Rotary switch



L. J. ELLIOTT ROTARY SWITCH July 7, 1964 2 Sheets-Sheet 1 Filed Oct. 27, 1961 INVENTOR. Lou/5 J. ELL. 1077 5 H/s A 7'7'0RA/EY5 HARE/.5, K/EcH, Russsu. &/(ERN y 1964 L. J. ELLIOTT 3,140,366

ROTARY SWITCH Filed Oct. 27, 1961 2 Sheets-Sheet 2 INVENTOR. Lou/s J. ELLIOTT BY HIS ATTORNEYS HARE/5, K/EcH, R0555 ci/(s/e/v United States Patent 3,140,366 ROTARY SWITCH Louis J. Elliott, Encinitas, Califi, assignor to Planautics Corp, Encinitas, Calif., a corporation of California Filed Oct. 27, 1961, Ser. No. 148,261 4 Claims. (Cl. 200- 24) the adverse effects of suchenvironmental conditions as vibration and shock.

It is a particular object of the invention to provide such a switch which may utilize high contact pressures in all of the circuits being switched without affecting the accuracy of operation. Another object is to provide such a switch in which the circuit closing and circuit opening edges of the contact wipers are remote from the working surfaces permitting closing and opening of circuits under relatively high load conditions.

It is an object of the invention to provide a rotary electrical switch including a tubular housing, a plurality of electrical contacts mounted in the housing, a rotor mounted within the housing for rotation about the axis of the housing, a plurality of contact wipers mounted on the rotor for selectively engaging the contacts to complete electric circuits between pairs of contacts, and means for rotating the rotor relative to the housing. A particular object is to provide such a structure in which the electric drive motor for the rotor is positioned within the rotor for driving the rotor relative to the housing. Another object is to provide such a structure incorporating a speed reduction transmission for coupling the motor to the rotor.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. The drawings merely show and the description merely describes a preferred embodiment of the present invention which is given by way of illustration or example.

In the drawings:

FIG. 1 is a longitudinal sectional view of a preferred embodiment of the invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged partial sectional along the line 4-4 of FIG. 3;

FIG. 5 is a perspective view of a contact for use in i the switch of FIG. 1;

FIG. 6 is a perspective view of a contact wiper for use in the switch of FIG. 1; and i FIG. 7 is a diagram illustrating one control circuit for operating the switch of FIG. 1.

The switch illustrated in the drawings includes a housing 10 formed of a tube 11 of electrical insulating material, an end plate 12 and another end plate 13. Brackets 14, 15 may be aflixed to the respective end plates for installing the switch. An electric motor 16 is mounted on the end plate 12 within the tube 11, with the motor shaft 17 journaled in a bearing 18 in the end plate 13.

The switch includes a rotor 21 mounted within the view taken 3,140,366 Patented July 7, 1964 housing for driving by the motor. In the form shown herein, the rotor comprises a tube 22 of electrical insulating material and an end plate 23. The open end of the rotor tube is journaled on a shoulder 24 of the housing end plate 12 and the end plate 23 of the rotor is supported on the motor shaft 17 by a bearing 25. A speed-reducing transmission 26 is provided for coupling the motor output shaft to the motor and a preferred form of the transmission is shown in FIGS. 1 and 2.

The speed-reducing transmisison includes a gear member 30 journaled on an eccentric sleeve 31 of the shaft 17 by a bearing 32. Gear teeth in the form of serrations 33 extend around the periphery of the gear member 30. Corresponding serrations 34 are provided on an inwardly facing shoulder 35 of the housing end plate 13 for engagement with the serrations 33. The gear member 30 engages the housing at one location, e.g., at the zone 36 in FIG. 2. As the motor shaft 17 rotates in one direction, the gear member 30 will rotate at a substan tially reduced rate, with the ratio being a function of the diameters of the eccentric sleeve 31 and the gear member 30.

A plurality of pins 40 are carried in the gear member 30 with the pins disposed in a circle about the center of the gear member. A corresponding plurality of openings 41 are provided in the rotor end plate 23, with the openings being larger than the pins and disposed in a circle about the center of the end plate. Engagement of the pins and openings provides a drive coupling between the gear member and the rotor so that the rotor rotates in synchronism with the gear member although about a different axis.

The rotary switch of the invention provides for switching of a large number of circuits in a relatively small volume and also permits operation with relatively high contact pressure thereby substantially eliminating contact noise and the possibility of open circuits. In the preferred embodiment disclosed herein, a plurality of contacts 44 are carried in the housing tube 11 and project into the interior of the tube for engagement by contact wipers 45 carried by the rotor tube 22. The contacts 44 may be arranged in sets and disposed in parallel planes positioned perpendicular to the axis of the tubes. In the particular embodiment illustrated, the contacts are arranged in four sets of three in each of twelve planes, providing a total of 144 contacts. Of course, various other arrangements of the contacts can be utilized as desired.

The contact 44 is a U-shaped structure with a central body 46, projecting arms 47, 48, and a terminal 49 (FIG. 5). The contacts are positioned in openings 50 in the housing tube 11 with the arms projecting into the interior of the tube. The contacts may be fixed to the tube by cementing, as indicated at 51 of FIG. 1. Wire conductors 52 are soldered or otherwise afiixed to the terminals 49 of the contacts as desired.

The contact wipers 45 are segments of rings of a length sufficient to span adjacent contacts for completing a circuit therebetween. The wipers are carried on the rotor tube 22 and may be molded in place or cemented in grooves provided in the surface of the rotor. The wipers may be provided with anchoring grooves 55, 56 in the side walls thereof to facilitate mounting in the rotor tube.

' The wipers are arranged in sets disposed in parallel planes corresponding to the planes of the contacts on the housing tube. A preferred arrangement for the wipers of a plane is shown in FIG. 3 wherein eight identical wipers are uniformly disposed about the rotor tube and the spacing between the sets of contacts is equal to the spacing between the end contacts of a set. With thisarrangement, and with the rotor and housing in the position of FIG. 3, a closed circuit is provided with each contact set. For example, with the contacts 57, 58, 59 of the set at the bottom of FIG. 3, a circuit is closed between contacts 57 and 58. Rotation of the rotor in either direction results in opening of the circuit between contacts 57, 58 and closing of a circuit between the contacts 58, 59. Further rotation of the rotor opens the circuit between contacts 58, 59 and again closes the circuit between contacts 57, 58. It should be noted that the contact structure of the invention may be used with reciprocating and translating motions as well as with rotational motion.

The rotor may be rotated continuously or stepwise in either direction as desired and various control mechanisms may be used for driving the motor. Also the rotor may be moved manually and/ or by means of solenoids or other suitable drive mechanisms. One circuit suitable for control of the rotary switch is shown in FIG. 7. The motor 16 is connected in series with a contact set 60 of a relay 61 across a source of power. The coil of the relay 61 is energized through a contact set 62 of a relay 63. The relay 61 is a slow release relay, which may be achieved by providing a capacitor 64 and resistor 65 in series across the relay coil. The coil of the relay 63 is energized from a power source through a switch 66 which may be manually operated or be controlled by some external means.

Closing of the switch 66 energizes the relay 63 and closes the contact set 62, which in turn energizes the relay 61 and closes the contact set 60, starting the motor 16. Actuation of the relay 63 also closes a contact set 67, establishing a holding circuit for the relay 63 through a switch contact 68, a switch wiper 69 and another switch contact 70. The circuit remains in this condition until the wiper 69, moving in the direction of the arrow 71, opens the circuit between the contacts 68, 70. Then the holding circuit is broken, de-energizing the relay 63 and opening the contact set 62 to de-energize the relay 61. The slow release relay 61 maintains the contact set 60 closed for a further period, permitting the motor to run and drive the contact wiper 72 to establish a new holding circuit between the contact 70 and the contact 73.

The control circuit is now ready for another switching cycle which may be initiated by momentarily closing the switch 66.

The motor 16 may be provided with a brake to prevent coasting and to provide precise control of wiper positioning. In the particular embodiment shown in FIG. 1, a disc 75 is fixed to the shaft 17 by a pin 76 and carries a brake surface material 77 at the edge thereof. A plate 78 is journaled on the shaft 17 for movement along the axis of the shaft but is keyed to the motor casing to prevent rotation of the plate. The plate may include a pro ection 79 which engages a mating opening in the motor casing. A spring 80 is positioned between the plate :78 and a portion of the motor casing for urging the plate into engagement with the brake disc to stop rotation of the disc. The plate 78 forms a portion of the magnetic circuit around a coil 81. The coil is energized when the motor is energized and pulls the plate 78 away from the plate disc against the action of the spring 80, permitting the motor shaft to turn. When the motor power is turned off, the coil is also de-energized and the spring actuates the brake.

The rotary switch of the invention provides a high torque drive for a large number of electric contacts. This high torque drive permits the contact pressure to be maintained high to substantially eliminate noise and the possibility of open circuits. The high contact pressure also permits a high current capacity for the circuits being switched. The contact wipers 45 move in a circular path so that the circuits are closed and opened at the leading and trailing edges 85, 86 of the wipers. But while stationary, the circuits are maintained through the sides of the contact wipers remote from the leading and trailing edges. Hence the rough, pitted and burned surfaces due to arcing and mechanical wear at opening and closing are maintained remote from the working surfaces.

The present invention provides a very compact and rugged electrical switch. In the specific embodiment illustrated herein, 144 contacts are provided in a switch which is about two and one-half inches in diameter and seven and one-half inches long. The switch provides high contact pressure with minimum noise and positive operation and will handle twenty-five amperes at one hundred volts on each circuit.

Although an exemplary embodiment of the invention has been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiment disclosed may be subjected to var1- ous changes, modifications and substitutions without necessarily departing from the spirit of the invention.

I claim as my invention:

1. In a rotary electrical switch, the combination of:

a tubular housing having an axis;

a plurality of electrical contacts mounted in said housing and projecting into the interior thereof;

a tubular rotor mounted within said housing for rotation about said axis;

a plurality of contact wipers mounted on said rotor forselectively engaging said contacts to complete electric circuits between adjacent contacts;

a motor supported by said housing and positioned within said rotor and having an output shaft;

first gear means journaled on said shaft for rotation about an axis displaced from the shaft axis;

second gear means carried in said housing for engaging said first gear means;

and coupling means for coupling said first gear means to said rotor for synchronous rotation of said first gear means and rotor.

2. In a rotary electrical switch, the combination of:

a tubular housing having an axis;

a plurality of relatively resilient electrical contacts mounted in said housing and projecting into the interior thereof, with said contacts arranged in sets disposed in parallel planes positioned perpendicular to said axis;

a tubular rotor mounted within said housing for rotation about said axis;

a plurality of relatively rigid contact wipers mounted on said rotor with said wipers arranged in sets disposed in said parallel planes, each of said wipers comprising an arcuate section projecting radially outward from said rotor and adapted to slidingly engage said contacts to complete electric circuits between pairs of contacts;

a motor supported by said housing and positioned within said rotor and having an output shaft;

first gear means journaled on said shaft for rotation about an axis displaced from the shaft axis;

second gear means carried in said housing for engaging said first gear means;

and coupling means for coupling said first gear means to said rotor for synchronous rotation of said first gear means and rotor for moving said wipers relative to said contacts.

3. In a contact structure for an electrical switch, the

combination of:

a housing;

a plurality of relatively resilient U-shaped electrical contacts mounted in said housing and projecting therefrom, with said contacts arranged in sets of three with the spacing between sets equal to the spacing between the end contacts of a set;

a moving member mounted on said housing for movement relative thereto;

a plurality of relatively rigid contact wipers mounted on said member with said wipers spaced from each other and arranged in sequence, each of said wipers comprising a unitary conducting bar projecting from said member and adapted to slide between the arms of said contacts to complete electric circuits between adjacent contacts of a set, with said arms providing gripping engagement of said Wipers;

and drive means supported by said housing and engaging said member for driving said member and moving said wipers relative to said contacts.

4. In a rotary electrical switch, the combination of:

a tubular housing having an axis;

a plurality of electrical contacts mounted in said housing and projecting into the interior thereof;

a tubular rotor mounted within said housing for rotation about said axis;

a plurality of contact wipers mounted on said rotor for selectively engaging said contacts to complete electric circuits between adjacent contacts;

a motor supponted by said housing and positioned within said rotor and having an output shaft;

first gear means journalled on said shaft for rotation about an axis displaced from the shaft axis;

second gear means carried in said housing for engaging said first gear means;

coupling means for coupling said first gear means to synchronous rotation;

a plurality of pins on one of said coupled elements with the pins positioned in a circle about the axis of rotation of said one element; and

a plurality of pin receiving means on the other of said coupled elements with said means including openings larger than said pins and positioned in a circle about the axis of rotation of said other element.

References Cited in the file of this patent UNITED STATES PATENTS 1,080,535 Brodie Dec. 9, 1913 1,187,315 Henry June 13, 1916 1,863,658 James June 21, 1932 2,475,504 Jackson July 5, 1949 2,565,643 Baddour Aug. 28, 1951 2,821,583 Kielman Jan. 28, 1958 2,825,768 Beck Mar. 4, 1958 2,938,970 Constantine May 31, 1960 FOREIGN PATENTS 1,191,013 France Apr. 6, 1959 UN-ITED 'sTXTEs OFFICE CERTIFICATE CDRRECTION Patent No. 3,140,366 July 7, 1964 Louis J. Elliott v It is hereby certified that-error"agpeers in the.above numbered pat: ent reqliring correction and that the sid Letters Patent should read as corrected below.

Column 2, line 8; for "motor" read r0t0r--d Signdafid Sealed this 17th day of November 1964.

Commissioner of Patents ERNEST W. SWIDER Altcsting Officer UNiTED "STATES OFFICE CERTIFICATE (IURRECTION Patent No. 3, 140,366 July 7 1964 v It is hereby certified-that e'rrorgappears in theiabeve numbered patent reqliring correction and that) the said" Letters Patentshould read as corrected below.

Column 2 line 8,= for "motor" read r0tor' Q Signed arid sealed this 17th day of November 1964.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Aitcsting Officer Commissioner of Patents 

1. IN A ROTARY ELECTRICAL SWITCH, THE COMBINATION OF: A TUBULAR HOUSING HAVING AN AXIS; A PLURALITY OF ELECTRICAL CONTACTS MOUNTED IN SAID HOUSING AND PROJECTING INTO THE INTERIOR THEREOF; A TUBULAR ROTOR MOUNTED WITHIN SAID HOUSING FOR ROTATION ABOUT SAID AXIS; A PLURALITY OF CONTACT WIPERS MOUNTED ON SAID ROTOR FOR SELECTIVELY ENGAGING SAID CONTACTS TO COMPLETE ELECTRIC CIRCUITS BETWEEN ADJACENT CONTACTS; A MOTOR SUPPORTED BY SAID HOUSING AND POSITIONED WITHIN SAID ROTOR AND HAVING AN OUTPUT SHAFT; FIRST GEAR MEANS JOURNALED ON SAID SHAFT FOR ROTATION ABOUT AN AXIS DISPLACED FROM THE SHAFT AXIS; SECOND GEAR MEANS CARRIED IN SAID HOUSING FOR ENGAGING SAID FIRST GEAR MEANS; AND COUPLING MEANS FOR COUPLING SAID FIRST GEAR MEANS TO SAID ROTOR FOR SYNCHRONOUS ROTATION OF SAID FIRST GEAR MEANS AND ROTOR. 